Most people who visit Fisherman’s Wharf in San Francisco know about the famous California sea lions that inhabit the Pier 39 docks. Locals and visitors alike adore observing and photographing the mammals as they play, nap, bark, fight and eat. California sea lions are the fastest and largest of their species – they can weigh over 800 pounds, grow to seven feet in length, swim up to 25 miles per hour, and live as long as 30 years.

Often referred to as “sea-lebrities,” this massive rookery of California sea lions has been a hot San Francisco tourist attraction since 1989. Last year, as many as 1,700 of these gigantic, whiskery sea creatures called Pier 39 home. But by late 2009, the sea lions inexplicably disappeared from the docks, causing sea-lebrity admirers to ask some serious questions. Was their food source of squid, herring and salmon dwindling? Were they anticipating an earthquake? Was El Niño to blame? Did they migrate somewhere? And… would they ever come back?

Now, several months after their departure, the California sea lions are slowly returning to Pier 39. The puzzling questions behind their initial Fisherman’s Wharf presence, sudden disappearance and eventual return remain unanswered, but sea-lebrity fans around the world are exhaling a sigh of relief.